CN114341245B

CN114341245B - Flame retardant polymer compositions and methods of use

Info

Publication number: CN114341245B
Application number: CN202080052525.3A
Authority: CN
Inventors: F·范塔索; M·博鲁尔基
Original assignee: Imerys Pigments Inc
Current assignee: Imerys Pigments Inc
Priority date: 2019-05-23
Filing date: 2020-05-22
Publication date: 2024-07-12
Anticipated expiration: 2040-05-22
Also published as: CN114341245A; EP3973017A4; EP3973017A1; BR112021023298A2; CA3141484A1; WO2020237157A1; US20220251332A1

Abstract

Flame retardant polymer compositions comprising a mineral blend melt mixed into a polymer matrix are described. The mineral blend comprises alkaline earth carbonate, kaolin clay and magnesium hydroxide. The polymer matrix may comprise ethylene vinyl acetate and polyethylene, and dicumyl peroxide may also be added. The flame retardant polymer composition exhibits a UL94 flammability rating of V-0 or V-1 and is free of halogen or aluminum hydroxide. The flame retardant polymer composition may be suitable as a wire coating, or for passive fire resistance in vehicles and buildings.

Description

Flame retardant polymer compositions and methods of use

Request priority

The PCT International application claims the benefit of priority from U.S. provisional application No. 62/851,833 filed on 5/23 in 2019, the subject matter of which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates to polymer compositions having flame retardant properties and comprising mineral blends of kaolin, alkaline earth carbonate and magnesium hydroxide.

Background

The description of "background art" provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

The production of flame retardant polymer compositions for various functions is well known in the art. The requirements for various flame retardant properties of the polymer composition may vary depending on the intended end use of the polymer composition. For example, the requirements regarding heat release, smoke generation, vertical flame propagation, smoke density, smoke acidity and melt viscosity may vary depending on the intended end use of the polymer composition. Accordingly, it is desirable to provide alternative and/or improved flame retardant polymer compositions.

In view of the foregoing, it is an object of the present disclosure to provide a polymer composition having flame retardant properties. The composition comprises a mineral blend of kaolin clay, alkaline earth carbonate and magnesium hydroxide. The compound may be halogen-free and aluminum hydroxide-free.

Disclosure of Invention

According to a first aspect, the present disclosure relates to a flame retardant polymer composition comprising a mineral blend and a polymer. The mineral blend is present in a weight percentage in the range of 20-80 wt% and the polymer is present in a weight percentage in the range of 20-80 wt%, each relative to the total weight of the flame retardant polymer composition. The mineral blend comprises kaolin clay, alkaline earth carbonate and magnesium hydroxide.

In one embodiment, the mineral blend comprises 10-50 wt% kaolin clay, 10-50 wt% alkaline earth carbonate, and 10-50 wt% magnesium hydroxide, each relative to the total weight of the mineral blend.

In one embodiment, the mineral blend is dispersed in the polymer.

In one embodiment, the kaolin is natural kaolin.

In one embodiment, the kaolin is a surface treated kaolin.

In one embodiment, the alkaline earth carbonate is at least one selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, huntite and magnesite.

In one embodiment, the polymer is a polyolefin.

In one embodiment, the polymer is an elastomer selected from the group consisting of alkyl acrylate copolymers (acrylic rubber), ethylene propylene diene rubber, ethylene vinyl acetate, fluoroelastomers, polybutadiene, polyisobutylene, polyisoprene, silicone rubber, and natural rubber.

In one embodiment, the polymer is a thermoplastic polymer selected from the group consisting of acrylic, acrylonitrile butadiene styrene, ethylene vinyl acetate, nylon, poly (vinyl acetate), polyacrylonitrile, polybenzimidazole, polybenzoxazole, polybenzothiazole, polybutene-1, polybutene, polycarbonate, polyethersulfone, polyetheretherketone, polyetherimide, polyethylene adipate, polyethylene terephthalate, polyimide, polylactic acid, polymethyl acrylate, polymethyl methacrylate, polymethylpentene, polyoxymethylene, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, polytetrafluoroethylene, polyvinyl alcohol, polyvinyl chloride, polyvinyl ester, and polyvinylidene fluoride.

In a further embodiment, the thermoplastic polymer comprises ethylene vinyl acetate and polyethylene.

In a further embodiment, the polyethylene is a linear low density polyethylene.

In one embodiment, the flame retardant polymer composition further comprises less than 5 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

In a further embodiment, the flame retardant polymer composition comprises less than 0.1 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

In one embodiment, the flame retardant polymer composition is substantially halogen free.

In one embodiment, the flame retardant polymer composition further comprises titanium dioxide.

In one embodiment, the flame retardant polymer composition further comprises 0.01 to 5 weight percent fatty acid, polysiloxane, or both, each relative to the total weight of the flame retardant polymer composition.

In a further embodiment, the fatty acid is stearin and the polysiloxane is PDMS.

In a further embodiment, the flame retardant polymer composition comprises both fatty acid and polysiloxane in a weight ratio of stearin to polysiloxane in the range of 1:1 to 6:1.

In one embodiment, the flame retardant polymer composition further comprises from 0.01 to 0.05 weight percent dicumyl peroxide, relative to the total weight of the flame retardant polymer composition.

In one embodiment, the density of the flame retardant polymer composition is in the range of 1.1 to 1.8g/cm ³.

In one embodiment, the flame retardant polymer composition has a melt flow rate in the range of 2.0 to 4.5cm ³/10 min at 150℃according to ASTM D1238-10.

In one embodiment, the flame retardant polymer composition has a melt flow rate in the range of 47-70 cm ³/10 min at 230℃according to ASTM D1238-10.

In one embodiment, the flame retardant polymer composition has a tensile strength at break in the range of 6 to 10MPa according to ASTM D638-14.

In one embodiment, the flame retardant polymer composition has a tensile strain at break in the range of 15 to 40% according to ASTM D638-14.

In one embodiment, the flame retardant polymer composition has a UL94 flammability rating of V-0 or V-1.

According to a second aspect, the present disclosure relates to an insulated wire product comprising a conductive wire coated with a layer of the flame retardant polymer composition of the first aspect.

According to a third aspect, the present disclosure relates to a method of preparing the flame retardant polymer composition of the first aspect. The method comprises melt mixing a polymer with a mineral blend selected from the group consisting of: (i) A blend comprising (e.g., with an aminosilane) surface-treated kaolin, an alkaline earth carbonate, and magnesium hydroxide; and (ii) a polysiloxane or fatty acid coated mineral blend comprising kaolin, alkaline earth carbonate and magnesium hydroxide.

In one embodiment of the method, the average diameter of the mineral blend (i) or (ii) is in the range of 0.5-10 μm.

In one embodiment of the method, the BET surface area of the mineral blend (i) or (ii) is in the range of 2-20 m ²/g.

In one embodiment of the method, the melt mixing is performed in a screw extruder having an RPM in the range of 100-300 and is heated at a temperature gradient having a maximum temperature in the range of 150-250 ℃.

In one embodiment of the method, the melt mixing comprises first melt mixing the polymer in a heated screw extruder and then adding the mineral blend to the heated screw extruder.

According to a fourth aspect, the present disclosure is directed to a method of forming a flame retardant object. The method includes heating the flame retardant polymer composition of the first aspect to form a molten composition. The surface of the object is then contacted with the molten composition to form a flame retardant object.

In one embodiment of the method, the object is an electrical conductor, an automotive part, a building material, an electronic device or an electrical appliance.

According to a fifth aspect, the present disclosure is directed to a method of forming a flame retardant object. The method includes injection molding the flame retardant polymer composition of the first aspect to form a flame retardant object.

In one embodiment of the method, the flame retardant object forms an outer shell or surface of an electrical conductor, an automotive part, a building material, an electronic device or an electrical appliance.

The preceding paragraphs have been provided by way of general introduction and are not intended to limit the scope of the appended claims. The embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

Drawings

A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Fig. 1 shows a logarithmic equation showing the temperature distribution of a screw extruder.

Fig. 2A shows a schematic diagram of a twin screw extruder.

Fig. 2B shows another schematic diagram of a twin screw extruder.

Fig. 3 shows the feeder throughput in zone 3 of the twin screw extruder.

Fig. 4A shows the torque during compounding of each sample.

Fig. 4B shows the average die pressure during compounding of each sample.

Figure 5 shows the compound density for each sample.

Figure 6A shows the melt flow rate of the compound at 150 ℃.

Fig. 6B shows the melt flow rate of the compound at 230 ℃.

Fig. 7A shows the tensile strength of the compounds.

Fig. 7B shows the tensile strain of the compound.

Figure 8 shows the feeder throughput for three minerals at zone 3.

Figure 9A shows the amperage of the extruder when extruding different compounds.

Fig. 9B shows the melt flow rate of the compounds.

Fig. 10A shows the tensile strength at break of the compound.

Fig. 10B shows the tensile strain at break of the compound.

Fig. 11A shows the tensile strength at break of compounds with and without DCP.

Fig. 11B shows the tensile strain at break of compounds with and without DCP.

Fig. 12A is a photograph of a sample containing DCP after a burn test.

Fig. 12B is a photograph of a sample without DCP after the burn test.

Fig. 13 shows the 20 ° gloss results for the compounds tested in example 5.

Fig. 14 shows the 60 ° gloss results for the compounds tested in example 5.

Detailed Description

Embodiments of the present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown.

The present disclosure will be better understood with reference to the following definitions. As used herein, the words "a" and "an" and the like have the meaning of "one or more". Within the description of the present disclosure, when numerical limits or ranges are stated, endpoints are included unless otherwise indicated. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, when describing magnitudes and/or positions, the word "about," "approximately," or "substantially similar" may be used to indicate that the described values and/or positions are within a reasonably expected range of values and/or positions. For example, a value may have +/-0.1% of the value (or range of values), +/-1% of the value (or range of values), +/-2% of the value (or range of values), +/-5% of the value (or range of values), +/-10% of the value (or range of values), +/-15% of the value (or range of values), or +/-20% of the value (or range of values). In the description of the present disclosure, where numerical limits or ranges are stated, endpoints are included unless otherwise indicated. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and may be abbreviated as "/".

The disclosure of values and ranges of values for specific parameters (e.g., temperature, molecular weight, weight percent, etc.) does not preclude the use of other values and ranges of values herein. It is contemplated that two or more specific example values for a given parameter may define the endpoints of a range of values that may be claimed for that parameter. For example, if parameter X is exemplified herein as having a value a and is also exemplified as having a value Z, it is contemplated that parameter X may have a range of values from about a to about Z. Similarly, the disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping, or different) is contemplated to encompass all possible combinations of ranges of values that may be claimed using the endpoints of the disclosed ranges. For example, if parameter X is exemplified herein as having a value in the range of 1-10, it is also contemplated that parameter X may have other ranges of values including 1-9, 2-9, 3-8, 1-3, 1-2, 2-10, 2.5-7.8, 2-8, 2-3, 3-10, and 3-9, by way of example only.

As used herein, the words "preferred" and "preferably" refer to embodiments of the technology that provide certain benefits in certain circumstances. However, other embodiments are also preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present technology.

As used herein, the word "comprise" and variations such that recitation of items in a list is not to the exclusion of other like items in materials, compositions, devices, and methods that may also be useful in this technology. Similarly, the terms "capable" and "may" and variants thereof are intended to be non-limiting such that recitation of an embodiment capable of or containing certain elements or features does not exclude other embodiments of the disclosure that do not contain those elements or features.

Although the terms "first" and "second" may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms unless otherwise indicated by the context. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and, similarly, a second feature/element discussed below could be termed a first feature/element, without departing from the teachings of the present disclosure.

Nothing in the above specification is intended to limit the scope of the claims to any particular composition or structure of components. Many alternatives, additions, or modifications are contemplated within the scope of the present disclosure and will be apparent to those skilled in the art. The embodiments described herein are given by way of example only and are not to be construed as limiting the scope of the claims.

As used herein, "compound" is intended to refer to a chemical entity, whether solid, liquid, or gas, and whether in a crude mixture or isolated and purified.

As used herein, "composite" refers to a combination of two or more different constituent materials combined into one. At the atomic level, the individual components remain separate and distinct in the final structure. These materials may have different physical or chemical properties that when combined result in a material having different characteristics than the original components. In some embodiments, the composite material may have at least two constituent materials that comprise the same empirical formula, but are distinguished by different densities, crystalline phases, or lack of crystalline phases (i.e., amorphous phases).

The present disclosure is intended to include all hydration states of a given compound or formula unless otherwise indicated or when the material is heated. For example, ni (NO ₃)₂ includes anhydrous Ni (NO ₃)₂、Ni(NO₃)₂·6H₂ O and any other hydrated forms or mixtures. CuCl ₂ includes both anhydrous CuCl ₂ and CuCl ₂·2H₂ O. Magnesite includes hydromagnesite.

Furthermore, the present disclosure is intended to include all isotopes of atoms present in the compounds and complexes of the invention. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and not limitation, isotopes of hydrogen include deuterium and tritium. Isotopes of carbon include ¹³ C and ¹⁴ C. Isotopes of nitrogen include ¹⁴ N and ¹⁵ N. Isotopes of oxygen include ¹⁶O、¹⁷ O and ¹⁸ O. Isotopes of magnesium include ²⁴Mg、²⁵ Mg and ²⁶ Mg. Isotopes of calcium include ⁴⁰Mg、⁴²Mg、⁴³Mg、⁴⁴ Mg and ⁴⁶ Mg. Isotopes of aluminum include ²⁶ Al and ²⁷ Al. Isotopically-labeled compounds of the present disclosure can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described herein using an appropriate isotopically-labeled reagent in place of an otherwise-used non-labeled reagent.

According to a first aspect, the present disclosure relates to a flame retardant polymer composition comprising a mineral blend and a polymer.

The mineral blend may be present in the flame retardant polymer composition in a weight percent in the range of 20 to 80 weight percent, or 30 to 75 weight percent, or 40 to 70 weight percent, or 50 to 65 weight percent, relative to the total weight of the flame retardant polymer composition. The mineral blend comprises kaolin clay, alkaline earth carbonate and magnesium hydroxide. In alternative embodiments, the mineral blend may comprise other minerals including, but not limited to, talc, mica, wollastonite, halloysite, and perlite. Other minerals listed below are also contemplated.

In one embodiment, the mineral blend is dispersed in the polymer. In one embodiment, the mineral blend dispersed in the polymer means that the concentration or density of the mineral blend in any continuous cubic region of 1 mm ³ volumes within the flame retardant polymer composition is less than 30% different, or less than 20% different, or less than 10% different, or less than 5% different from the bulk (or average) concentration or density of the mineral blend in the polymer. In some embodiments, the flame retardant polymer composition may be spread as a thin layer, where there may not be 1 mm ³ consecutive cubic volumes, in which case a similar definition may be applied to smaller cubic volumes, such as 0.1 mm ³、0.01 mm³ or 0.001 mm ³.

The mineral blend may comprise kaolin in a weight percent in the range of 10 to 50 wt%, or 20 to 40 wt%, or 0 to 35 wt%, or about 33 wt%, relative to the total weight of the mineral blend. Kaolin includes the minerals kaolinite, dickite, halloysite and nacreous china clay. Kaolinite is a clay mineral, a part of the group of industrial minerals, with a chemical composition Al ₂Si₂O₅(OH)₄. It is a layered silicate mineral, silica (SiO ₄) having a tetrahedral sheet octahedral connected to an alumina (AlO ₆) of the octahedral sheet by oxygen atoms. In one embodiment, the kaolin may be present as particles having a median particle size (d ₅₀) in the range of 0.2 to 5 μm, or 0.8 to 2 μm, or 0.9 to 1.9, or 0.9 to 1.5 μm. In one embodiment, the median particle size is no greater than 1.9 μm.

For example, certain very coarse kaolins have a particle size distribution such that less than about 70% by weight of the particles, less than about 60% by weight of the particles, or less than about 50% by weight of the particles have a particle size of less than 2 microns as measured by Sedigraph. In contrast, the particle size distribution of the very fine kaolin may be such that greater than 80 wt% of the particles, greater than 85 wt% of the particles, greater than 90%, or even greater than 95 wt% of the particles have a particle size of less than 2 microns, as measured by Sedigraph.

Another way to observe the kaolin size is by its fine particle content. For example, some very fine kaolin clay may have a particle size distribution such that greater than 20 wt% of the particles, greater than 25 wt% of the particles, greater than 30%, greater than 40%, or even greater than 50 wt% of the particles have a particle size of less than 0.25 microns, as measured by Sedigraph. In contrast, the coarse kaolin may have a particle size distribution such that less than 20 wt% of the particles, less than 15 wt% of the particles, or even less than 10 wt% of the particles have a particle size of less than 0.25 microns, as measured by Sedigraph.

Kaolin may have a wide variety of particle shapes. For example, some bulk kaolins have a shape factor of less than about 15, such as less than about 12, less than about 10, less than about 8, less than about 6, or even less than about 4. Other platy kaolins can have a shape factor of greater than about 15, for example greater than about 20, greater than about 25, greater than about 30, greater than about 35, greater than about 40, greater than about 50, greater than about 70, or even greater than about 100.

As used herein, a "form factor" is a measure of the ratio of the particle size to the particle thickness of a population of particles of different sizes and shapes, as measured using the conductivity method, apparatus, and equation described in U.S. patent No. 5,576,617. As described in the' 617 patent, the conductivity of the composition of the aqueous suspension of oriented particles under test is measured as the composition flows through the container. The measurement of conductivity is performed in one direction of the container and in another direction of the container transverse to the first direction. The difference between the two conductivity measurements is used to determine the form factor of the particulate material under test.

In one embodiment, the kaolin is natural kaolin, meaning that the kaolin is derived from the environment and is not calcined (i.e., is not subjected to heat above 500 ℃) or derived from the environment and is not processed beyond mechanical processing (grinding, sieving, granulating, etc.). In one embodiment, the kaolin may be calcined kaolin or hydrous kaolin. In one embodiment, the kaolin to be used in the mineral blend may be surface treated kaolin. The surface treatment agent may be an aminosilane including, but not limited to, APTES (gamma-aminopropyl triethoxysilane), APDEMS ((3-aminopropyl) -diethoxy-methylsilane), APDMES ((3-aminopropyl) -dimethyl-ethoxysilane), APTMS ((3-aminopropyl) -trimethoxysilane).

The mineral blend may comprise one or more alkaline earth carbonates in a total weight percentage in the range of 10-50 wt%, or 20-40 wt%, or 30-35 wt%, or about 33 wt%, relative to the total weight of the mineral blend. In one embodiment, the alkaline earth carbonate is at least one selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, huntite and magnesite. The alkaline earth carbonate may comprise a mixture of one or more alkaline earth carbonates, for example the two may be present in a weight ratio in the range of 1:100-100:1, or 1:10-10:1, or 1:2-2:1. In preferred embodiments, the alkaline earth carbonate is dolomite, which may also be referred to as calcium magnesium carbonate or CaMg (CO ₃)₂. In one embodiment, the alkaline earth carbonate may be present as particles having a median particle size (d ₅₀) in the range of 0.5-5 [ mu ] m, or 0.8-2.5 [ mu ] m, or 0.9-1.5 [ mu ] m.

The mineral blend may comprise magnesium hydroxide in a weight percentage in the range of 10-50 wt%, or 20-40 wt%, or 30-35 wt%, or about 33 wt%, relative to the total weight of the mineral blend. Magnesium hydroxide may be referred to as MDH. The magnesium hydroxide may be, for example, brucite, chlorite, or a combination of one or more thereof. In one embodiment, the alkaline earth carbonate may be present as particles having a median particle size (d ₅₀) in the range of 0.5-5 μm, or 0.8-2.5 μm, or 0.9-1.5 μm. In one embodiment, the median particle size is no greater than 2.5 μm.

When obtaining particulate minerals (e.g., kaolin) from naturally occurring sources, it is likely that some mineral impurities will inevitably contaminate the abrasive material. For example, naturally occurring kaolin may be present in combination with other minerals (e.g., dolomite). In addition, in some cases, other minerals may be included in small additions, for example, one or more of dolomite, talc, wollastonite, bauxite, or mica may also be present. Typically, however, the minerals used in the mineral blend will each comprise less than 5% by weight, such as less than 2% by weight, such as less than 1% by weight, of other minerals.

In some embodiments, the granular minerals each independently undergo minimal processing after mining or extraction. In a further embodiment, the particulate mineral is subjected to at least one physical modification method. The skilled artisan will readily appreciate the physical modification methods suitable for use, which may be now known or later discovered; suitable physical modification methods include, but are not limited to, comminution (e.g., crushing, grinding, milling), drying, and classification (e.g., air classification, hydraulic selection, screening, and/or sieving). In yet other embodiments, the particulate minerals are each independently subjected to at least one chemical modification process. The skilled artisan will readily appreciate the chemical modification methods suitable for use with the present compounds and methods, which may be now known or later discovered; suitable chemical modification methods include, but are not limited to, silylation and calcination. The particulate kaolin material may be surface treated or non-surface treated, for example. The surface treatment may, for example, be used to alter the properties of the kaolin particles and/or the compositions into which they are incorporated. In one embodiment, the surface treatment is performed by aminosilanes including, but not limited to, APTES (γ -aminopropyl triethoxysilane), APDEMS ((3-aminopropyl) -diethoxy-methylsilane), APDMES ((3-aminopropyl) -dimethyl-ethoxysilane), APTMS ((3-aminopropyl) -trimethoxysilane).

In certain embodiments, the surface treatment agent for kaolin is present in an amount up to about 5% by weight, based on the total weight of the particulate mineral, for example, from about 0.001% to about 5% by weight, or from about 0.01% to about 2% by weight, or from about 0.1% to about 2% by weight, or from about 0.5% to about 1.5% by weight, based on the total weight of the particulate mineral. In certain embodiments, the particulate mineral is not surface treated.

In one embodiment, the median particle size (d ₅₀) of the mineral blend may be in the range of 0.5-3 [ mu ] m, or 0.8-2.3 [ mu ] m, or 0.9-1.9 [ mu ] m, or 0.9-1.6 [ mu ] m, or 0.9-1.5 [ mu ] m. In one embodiment, the median particle size is not greater than 2.3 μm. In some embodiments, the mineral blend may be granulated and milled to obtain certain particle sizes. In one embodiment, the residual moisture content of the mineral blend may be 3 wt% or less, or 2 wt% or less, or 1 wt% or less, or 0.7 wt% or less, or 0.1 wt% or less, relative to the total weight of the mineral blend. In one embodiment, the oil absorption of the mineral blend may be 30 g/100 g or less, or 20 g/100 g or less, or 15 g/100 g or less, or 10 g/100 g or less, or 5 g/100 g or less. The oil absorption can be measured with linseed oil or some other oil. These properties described above and below may be for mineral blends with or without hydrophobic coatings or other surface treatments.

As used herein, "BET surface area" refers to the surface area of a particle of particulate talc material, relative to unit mass, as determined by the amount of nitrogen adsorbed on the surface of the particle to form a monolayer completely covering the surface, according to the BET method (as measured according to AFNOR standards X11-621 and 622 or ISO 9277). In certain embodiments, the BET surface area is determined according to ISO 9277 or any equivalent method thereof. In one embodiment, the surface area of the mineral blend may be 0.1 to 15 m ²/g, or 1 to 12 m ²/g, or 2 to 10m ²/g, or 3 to 8 m ²/g. In one embodiment, the surface area of the mineral blend may be no greater than 9m ²/g.

In one embodiment, mixing the mineral blend in water may produce an aqueous mixture having a conductivity in the range of 0-200 μS/cm, or 20-180 μS/cm, or 40-170 μS/cm, or 50-150 μS/cm. In one embodiment, the conductivity may be no greater than 170 μS/cm. Herein, the mineral blend may be present in the aqueous mixture in a weight percentage in the range of 0.1-75 wt%, 1-40 wt%, 2-30 wt%, relative to the total weight of the aqueous mixture, and the temperature of the aqueous mixture may be in the range of 20-32 ℃. In one embodiment, the loss on ignition of the mineral blend at 800 ℃ may be in the range of 1-35 wt%, 2-30 wt%, 3-20 wt%, or 4-10 wt%. In one embodiment, the loss on ignition of the mineral blend at 800 ℃ may be no greater than 29 wt%. In one embodiment, the bulk density of the mineral blend may be in the range of 0.50 to 1.20 g/cm ³, or 0.55 to 1.10 g/cm ³, or 0.60 to 1.00 g/cm ³, or 0.65 to 0.85 g/cm ³.

In one embodiment, the polymer is present in the flame retardant polymer composition in a weight percent in the range of 20 to 80 weight percent, or 25 to 70 weight percent, or 30 to 60 weight percent, or 35 to 50 weight percent, relative to the total weight of the flame retardant polymer composition. In one embodiment, the polymer is present in the form of a polymer matrix.

In one embodiment, the polymer is a polyolefin. Polyolefins are polymers of relatively simple olefins (e.g., ethylene, propylene, one or more butenes, one or more isoprenes, and one or more pentenes) and include copolymers and modifications as disclosed in Dictionary of Plastics, page 252 (Technomic Publications, 1978) of Whittington.

In one embodiment, the polymer is an elastomer. An "elastomer" is a rubbery polymer that can be stretched to at least twice its original length under tension and quickly retract to its original size when the stretching force is released. The elastic modulus of the elastomer is typically less than about 6,000 psi and elongation is typically greater than 200% in the uncrosslinked state at room temperature according to the method of ASTM D412.

In one embodiment, the polymer is an elastomer selected from the group consisting of alkyl acrylate copolymers (acrylic rubber), ethylene propylene diene monomer (EPDM rubber). In one embodiment, the surface treatment is performed by aminosilanes including, but not limited to, APTES (γ -aminopropyl triethoxysilane), APDEMS ((3-aminopropyl) -diethoxy-methylsilane), APDMES ((3-aminopropyl) -dimethyl-ethoxysilane), APTMS ((3-aminopropyl) -trimethoxysilane), fluoroelastomers, polybutadiene, polyisobutylene (PIB), polyisoprene, silicone rubber, and natural rubber.

In one embodiment, the polymer is a thermoplastic polymer. "thermoplastic" materials are linear or branched polymers that can repeatedly soften and become flowable when heated, and then return to a hard state when cooled to room temperature. The modulus of elasticity is typically greater than 10,000 psi according to the method of ASTM D638. In addition, the thermoplastic may be molded or extruded into any predetermined shaped article when heated to a softened state. In some embodiments, the polymer may be considered to be both an elastomer and a thermoplastic.

In one embodiment, the polymer is a thermoplastic polymer selected from the group consisting of: acrylic acid, acrylonitrile butadiene styrene, ethylene Vinyl Acetate (EVA), nylon (polyamide), poly (vinyl acetate), polyacrylonitrile, polybenzimidazole, polybenzoxazole, polybenzothiazole, polybutene-1 (PB-1), polybutene, polycarbonate, polyethersulfone, polyetheretherketone, polyetherimide, polyethylene adipate (PEA), polyethylene terephthalate (PET or PETE), polyimide, polylactic acid (PLA), polymethyl acrylate, polymethyl methacrylate, polymethylpentene (PMP), polyoxymethylene (acetal), polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, polytetrafluoroethylene, polyvinyl alcohol, polyvinyl chloride, polyvinyl ester (formula- [ RCOOCHCH ₂ ] -) and polyvinylidene fluoride.

In a preferred embodiment, the polymer is a thermoplastic polymer and is ethylene vinyl acetate, polyethylene or a blend of the two. In a further embodiment, the polymer is a blend of both ethylene vinyl acetate and polyethylene. The ethylene vinyl acetate may be present in the blend in a weight percent of 1 to 99 wt%, or 10 to 90 wt%, 20 to 80 wt%, 30 to 70 wt%, or 40 to 60 wt%, relative to the total weight of the polymer. Likewise, the polyethylene may be present in the blend in a weight percent of from 1 to 99 weight percent, preferably from 10 to 90 weight percent, from 20 to 80 weight percent, from 30 to 70 weight percent, or from 40 to 60 weight percent, relative to the total weight of the polymer. In one embodiment, the ethylene vinyl acetate is Braskem HM 728. In one embodiment, the polyethylene is Braskem LH 218.

Ethylene vinyl acetate is an elastic polymer that produces a material that is "rubbery" in terms of softness and flexibility. The material has good transparency and glossiness, low-temperature toughness, stress cracking resistance, hot melt adhesive waterproof property and UV radiation resistance. Ethylene vinyl acetate, also known as poly (ethylene vinyl acetate) (PEVA), is a copolymer of ethylene and vinyl acetate. The weight percentage of vinyl acetate typically varies from 10 to 40%, the remainder being ethylene. Ethylene vinyl acetate can be divided into three groups based on vinyl acetate content.

Ethylene vinyl acetate having a low proportion of vinyl acetate (about up to 4 wt%) may be referred to as vinyl acetate modified polyethylene. It is a copolymer and is processed into thermoplastic materials similar to low density polyethylene. It has some of the properties of low density polyethylene but increases gloss, softness and flexibility.

Ethylene vinyl acetate having a moderate proportion of vinyl acetate (4-30 wt%) is known as thermoplastic ethylene vinyl acetate copolymer and is a thermoplastic elastomeric material. It is not vulcanized, but has some properties of rubber or plasticized polyvinyl chloride, especially with higher amounts of vinyl acetate. Ethylene vinyl acetate having 9-13 wt% vinyl acetate may be used as the hot melt adhesive.

Ethylene vinyl acetate having a relatively high concentration of vinyl acetate (e.g., greater than 40 wt.%) may be referred to as ethylene vinyl acetate rubber.

Polyethylene (PE) is a common type of plastic, most of which has the formula (C ₂H₄)_n and has different degrees of branching PE is typically a mixture of similar polymers of ethylene with various n values polyethylene is a thermoplastic, however, when modified it can become a thermoset (e.g. cross-linked polyethylene) the macromolecules are not covalently linked.

Polyethylenes can be classified according to their density and branching. Its mechanical properties are obviously dependent on variables such as the degree and type of branching, crystal structure and molecular weight. Types of polyethylene include, but are not limited to, ultra High Molecular Weight Polyethylene (UHMWPE), ultra low molecular weight polyethylene (ULMWPE or PE-WAX), high Molecular Weight Polyethylene (HMWPE), high Density Polyethylene (HDPE), high density crosslinked polyethylene (HDXLPE), crosslinked polyethylene (PEX or XLPE), medium Density Polyethylene (MDPE), linear Low Density Polyethylene (LLDPE), low Density Polyethylene (LDPE), very Low Density Polyethylene (VLDPE), and Chlorinated Polyethylene (CPE).

In a further embodiment, the polyethylene is a Linear Low Density Polyethylene (LLDPE). Linear low density polyethylene is a substantially linear polyethylene having a significant number of short chain branches, typically produced by copolymerizing ethylene with long chain olefins. LLDPE may be defined by a density in the range of 0.915 to 0.925g/cm ³. Linear low density polyethylene differs structurally from conventional Low Density Polyethylene (LDPE) by the absence of long chain branching. Linearity of LLDPE comes from different manufacturing processes of LLDPE and LDPE. Generally, LLDPE is produced by copolymerizing ethylene with higher alpha-olefins (e.g., butene, hexene or octene) at lower temperatures and pressures. The copolymerization process produces LLDPE polymers which have a narrower molecular weight distribution than conventional LDPE and which combine with linear structures and significantly different rheological properties.

In one embodiment, the polyethylene may be an olefin-based block copolymer comprising a polymer block comprised of ethylene and ethylene alpha-olefin copolymer blocks. Herein, polyethylene may consist essentially of ethylene, with the remainder of the structure being different monomer units. Other monomer units include, for example, 1-propene, 1-butene, 2-methylpropene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene. Alpha-olefins having a carbon-carbon double bond at the terminal carbon atom and having a carbon number of 3 to 8 are preferred, such as 1-propylene, 1-butene, 1-hexene and 1-octene.

In one embodiment, the flame retardant polymer composition further comprises less than 5 wt%, or less than 4 wt% aluminum hydroxide, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.1 wt%, relative to the total weight of the flame retardant polymer composition. In one embodiment, the flame retardant polymer composition may be substantially free of aluminum hydroxide, meaning that the flame retardant polymer composition comprises less than 0.01 weight percent aluminum hydroxide, or less than 0.001 weight percent aluminum hydroxide, or 0 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition. Aluminum hydroxide may be referred to as ATH. The aluminum hydroxide may be, for example, gibbsite, bayerite, neo-alumina, alumina polyhydrate, or a combination of one or more thereof.

In one embodiment, the flame retardant polymer composition is substantially halogen free, meaning that the flame retardant polymer composition comprises less than 0.01 weight percent halogen, or less than 0.001 weight percent halogen, or 0 weight percent halogen, relative to the total weight of the flame retardant polymer composition. In one embodiment, the flame retardant polymer composition does not comprise carbon black, diatomaceous earth, xylene, and/or zinc oxide.

The halogen may be an organohalogen compound. The organohalogen compound can be, for example, an organic chloride (e.g., a chlorauric acid derivative, chlorinated paraffin), an organic bromide (e.g., decabromodiphenyl ether, decabromodiphenyl ethane, brominated polystyrene, brominated carbonate oligomer, brominated epoxy oligomer, tetrabromophthalic anhydride, tetrabromobisphenol a, hexabromocyclododecane), a halogenated organic phosphate (e.g., tris (1, 3-dichloro-2-propyl) phosphate, tetra (2-chloroethyl) dichloroisopentyl diphosphate), or a combination of one or more thereof.

In one embodiment, the flame retardant polymer composition is substantially free of phosphorus-and nitrogen-containing compounds, meaning that the flame retardant polymer composition comprises less than 0.01 wt%, or less than 0.001 wt%, or 0 wt% of these compounds, in total, relative to the total weight of the flame retardant polymer composition. The phosphorus-and/or nitrogen-containing compound may be, for example, red phosphorus, a phosphate ester, a polyphosphate ester (e.g., melamine polyphosphate), an organic phosphate ester (e.g., triphenyl phosphate (TPP), resorcinol bis (diphenyl phosphate) (RDP), bisphenol A Diphenyl Phosphate (BADP), tricresyl phosphate (TCP)), a phosphonate ester (e.g., dimethyl methylphosphonate (DMMP)), a phosphonite ester (e.g., aluminum diethylphosphonite), a halogenated organic phosphate ester (e.g., tris (1, 3-dichloro-2-propyl) phosphate, tetra (2-chloroethyl) dichloropentyl diphosphate), a phosphazene, polyphosphazene, triazine, or a combination of one or more thereof.

In one embodiment, the flame retardant polymer composition further comprises titanium dioxide. In one embodiment, the titanium dioxide may be Tiona RKB 2. The titanium dioxide may be present in a weight ratio in the range of 0.01 to 2.00 wt%, or 0.1 to 1.00 wt%, or 0.40 to 0.80 wt%, relative to the total weight of the flame retardant polymer composition. In one embodiment, titanium dioxide may be used as the pigment. However, other inorganic pigments or organic dyes may be used in addition to or in place of titanium dioxide. Other inorganic pigments include, but are not limited to, barium sulfate, antimony (III) oxide, lithopone, zinc oxide, manganese dioxide, iron oxide, and malachite. Organic dyes include, but are not limited to, azo dyes, carmine, naphthol red, and indigo. In one embodiment, other dyes, pigments or colorants suitable for the polymer compound may be used.

In one embodiment, the flame retardant polymer composition consists of kaolin (surface treated or untreated as described above), alkaline earth carbonate, magnesium hydroxide, and a polymer. In one embodiment, the flame retardant polymer composition consists of kaolin (surface treated or untreated), alkaline earth carbonate, magnesium hydroxide, polymer and titanium dioxide.

In one embodiment, the flame retardant polymer composition further comprises from 0.01 to 5 wt%, or from 0.1 to 3 wt%, or from 0.5 to 2 wt%, or from 0.6 to 1.6 wt% of a fatty acid, a polysiloxane, or both, each relative to the total weight of the flame retardant polymer composition. In one embodiment, the total weight percent of fatty acids and/or polysiloxanes is no greater than 1.6 weight percent. Fatty acids, silicones, or both can be added to the mineral blend to form a hydrophobic coating on the mineral blend. According to one embodiment, the kaolin used in the mineral blend coated with the hydrophobic coating is not treated with an aminosilane. In another embodiment, the mineral blend comprising surface treated kaolin (e.g., treated with an aminosilane) is not coated with a hydrophobic coating. In one embodiment, the fatty acid may be a saturated fatty acid, including but not limited to butyric, valeric, caproic, enanthic, caprylic, pelargonic, capric, undecylic, lauric, tridecylic, myristic, pentadecylic palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachic acid, hendecanoic acid, behenic acid, melissic acid, tetracosanoic acid palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachic acid di-undecanoic acid, behenic acid, triacontanoic acid, tetracosanoic acid. In other embodiments, unsaturated fatty acids may be used as fatty acids, or may be used in combination with saturated fatty acids. In other embodiments, in addition to fatty acids, some other lipids including saturated lipid tails may be used, including but not limited to lipids classified as glycerolipids, glycerophospholipids, sphingolipids, triglycerides, sterol lipids, isopentenol lipids, and glycolipids. In other embodiments, waxy or oily compounds, such as petroleum distillates, petrolatum, paraffin, asphaltenes or waxes, may be used in addition to fatty acids or other lipids.

In one embodiment, the polysiloxane can be Polydimethylsiloxane (PDMS), polymethylhydrosiloxane (PMHS), tetrakis (trimethylsiloxy) silane (TTMS), 2, 6-cis-diphenyl-hexamethyl-cyclotetrasiloxane ("Quadrosilan"). In another embodiment, the polysiloxane may comprise the following monomer units: hexamethylcyclotrisiloxane, octamethyltetrasiloxane, decamethylcyclopentasiloxane, methylsiloxane, ethylsiloxane, propylsiloxane, pentylsiloxane, dodecamethylcyclohexasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, tetradecyltetrasiloxane, silicone resins, silicone grease, silicone rubber and/or silicone oil. The room temperature viscosity of the polysiloxane may be in the range of 300 ≡400 cP, or 320 ≡380 cP, or about 350 cP. In one embodiment, in addition to the polysiloxane, the mineral blend may be silanized, for example by reaction with APTES ((3-aminopropyl) -triethoxysilane), APDEMS ((3-aminopropyl) -diethoxy-methylsilane), APDMES ((3-aminopropyl) -dimethyl-ethoxysilane), APTMS ((3-aminopropyl) -trimethoxysilane), GPMES ((3-glycidoxypropyl) -dimethyl-ethoxysilane), MPTMS ((3-mercaptopropyl) -trimethoxysilane), MPDMS ((3-mercaptopropyl) -methyl-dimethoxysilane) or some other silane. However, in some embodiments, the mineral blend may be silanized and then additionally coated with a polysiloxane and/or fatty acid.

In a further embodiment, the fatty acid is stearin (or stearic acid) and the polysiloxane is PDMS. In a further embodiment, the flame retardant polymer composition comprises both fatty acids and polysiloxanes in a weight ratio of stearin:polysiloxane range of from 1:1 to 6:1 (preferably from 2:1 to 5.5:1, or from 3:1 to 5:1, or at least 3:1).

In one embodiment, the mineral blend may be mixed with fatty acid and/or polysiloxane in a V-type reverse mixer and homogenized for 10 to 60 minutes, or 15 to 40 minutes, or about 20 minutes. In one embodiment, mixing the mineral blend with the fatty acid and/or polysiloxane may cause particles of the mineral blend to agglomerate and adhere to one another. However, in some embodiments, the particles may remain separate.

In one embodiment, the flame retardant polymer composition consists of a polymer, kaolin, alkaline earth carbonate, magnesium hydroxide, fatty acid and polysiloxane. In one embodiment, the flame retardant polymer composition consists of a polymer, kaolin, alkaline earth carbonate, magnesium hydroxide, fatty acid, polysiloxane, and titanium dioxide.

In one embodiment, fatty acids and/or polysiloxanes are added or coated onto the surface of the particles of the mineral blend prior to melt mixing into the polymer matrix. The fatty acids and/or polysiloxanes may impart hydrophobicity to the mineral blend particles, which may enable them to be more easily mixed and dispersed into the polymer matrix. In one embodiment, a commercial formulation (e.g., iragnox 1010) may be added to the mineral blend.

In one embodiment, the mineral blend may be in the form of particles or granules having a spherical or substantially spherical shape (i.e., wherein the sides are rounded or completely rounded), with a spongy (i.e., porous) appearance. As defined herein, having a substantially spherical shape means that the distance from the center of mass (center of mass) of the particle to anywhere on the outer surface of the particle varies by less than 30%, or less than 20%, or less than 10% of the average distance.

In some embodiments, a portion of the particles or fines of the mineral blend may be angular (angular pointed and jagged), sub-angular or sub-rounded, and have a jagged lamellar morphology. In one embodiment, the mineral blend may comprise a high aspect ratio specific material. The term "high aspect ratio particulate mineral" refers to minerals having acicular or lamellar particles. Layered particles generally have a small, flat and flaky or platy appearance. Needle-like particles generally have a long, fine fiber or needle-like appearance.

In one embodiment, the particles or fines of the mineral blend are monodisperse, having a coefficient of variation or relative standard deviation, expressed as a percentage and defined as the ratio of the standard deviation of particle size (σ) to the average value of particle size (μ) multiplied by 100%, of less than 25%, or less than 10%, or less than 8%, or less than 6%, or less than 5%. In one embodiment, the particles are monodisperse and have a particle size distribution in the range of 80% to 120% or 85-115% of the average particle size. In another embodiment, the particles are not monodisperse, e.g., they may be considered to be polydisperse. The coefficient of variation herein may be greater than 25% or greater than 37%. In one embodiment, the particles or granules are polydisperse with a particle size distribution in the range of 70% to 130% of the average particle size, or in the range of 60-140% or 50-150%. In one embodiment, the morphology of the mineral blend does not change significantly when mixed into the polymer. In other embodiments, the mineral blend may split and form smaller particles when mixed into the polymer.

In one embodiment, the flame retardant polymer composition further comprises from 0.01 to 0.05 weight percent, or from 0.02 to 0.04 weight percent dicumyl peroxide (DCP), relative to the total weight of the flame retardant polymer composition. In another embodiment, the flame retardant polymer composition comprises from 0.001 to 0.50 weight percent, from 0.005 to 0.20 weight percent, from 0.01 to 0.10 weight percent, or from 0.02 to 0.08 weight percent dicumyl peroxide. In one embodiment, the flame retardant polymer composition comprises about 0.03 weight percent dicumyl peroxide. In other embodiments, the flame retardant polymer composition may comprise some other organic peroxide in place of, or in addition to, dicumyl peroxide. For example, the flame retardant polymer composition may comprise an organic peroxide including, but not limited to, acetone peroxide, acetone hydrazone, alkenyl peroxide, arachidonic acid 5-hydroperoxide, artelinic acid (ARTELINIC ACID), benzoyl peroxide, α -bis (t-butylperoxy) diisopropylbenzene, bis (trimethylsilyl) peroxide, t-butylhydroperoxide, t-butylperoxybenzoate, cumene hydroperoxide, di-t-butylperoxide, diacetyl peroxide, diethyl ether peroxide, dihydroartemisinin, dimethyldioxirane, 1, 2-dioxane, 1, 2-dioxirane, dipropyl peroxydicarbonate, ergosterol peroxide, hexamethylenetrioxyenediamine, methyl ethyl ketone peroxide, p Meng Wanqing peroxide, peroxyacetyl nitrate, and/or 1,2, 4-trioxane.

In one embodiment, the flame retardant polymer composition consists of a polymer, kaolin, alkaline earth carbonate, magnesium hydroxide, fatty acid, polysiloxane, and dicumyl peroxide. In one embodiment, the flame retardant polymer composition consists of a polymer, kaolin, alkaline earth carbonate, magnesium hydroxide, fatty acid, polysiloxane, dicumyl peroxide, and titanium dioxide.

In one embodiment, the flame retardant polymer composition may comprise other additives, including but not limited to other polymeric or elastomeric materials, silica, perlite, talc, diatomaceous earth, zinc oxide, sodium bicarbonate, gypsum, calcium silicate, sodium silicate, potassium silicate, magnesium oxide, glass, feldspar, cement, lignin sulfonate, magnesium nitrate, calcium oxide, bentonite, melamine, poly [ (hydroxy phenylene) methylene ], carbon fiber, spinel oxide, clay, belite (2cao.sio ₂), alite (3cao.sio ₂), diatomaceous earth (3cao.al ₂O₃), or huntite (4cao.al ₂O₃·Fe₂O₃), mica, other carbonates, other ceramic fillers, carbon black, fibers, glass fibers, metal hydrates, borates, red phosphorus, other oxides, reinforcing agents, UV stabilizers, light stabilizers mold release agents, processing aids, nucleating agents, pigments, coupling agents (e.g., maleic anhydride grafted polyolefin), compatibilizing agents (e.g., maleic anhydride grafted polyolefin), opacifying agents, pigments, colorants, slip agents (e.g., erucamide), antioxidants, anti-fogging agents, antistatic agents, antiblocking agents, moisture barrier additives, gas barrier additives, dispersants, hydrocarbon waxes, stabilizers, co-stabilizers, lubricants, agents to improve toughness, agents to improve heat formation stability, agents to improve processability, processing aids (e.g., polybatch AMF-705), mold release agents (e.g., zinc salts, calcium salts, magnesium salts, lithium salts, organic phosphates, stearic acid, zinc stearate, silicone rubber, zinc salts, silicone rubber, and the like of fatty acids, calcium stearate, magnesium stearate, lithium stearate, calcium oleate, zinc palmitate), antioxidants and plasticizers. The flame retardant polymer composition may comprise commercial additives such as Polybond 3200, bluesil MF, irganox 1010, irganox 168 and/or Irganox B215. The flame retardant polymer composition may comprise one or more additives in a weight percentage of 0.1 to 10 wt%, or 0.2 to 5 wt%, or 0.5 to 1 wt%, relative to the total weight of the flame retardant polymer composition. In one embodiment, any of the above additives may not be present in the flame retardant polymer composition.

In one embodiment, the density of the flame retardant polymer composition is in the range of 1.1 to 1.8 g/cm ³、1.2-1.7 g/cm³,1.3-1.6 g/cm³, or 1.4 to 1.5 g/cm ³. In one embodiment, the flame retardant polymer composition has a melt flow rate at 150℃in the range of 2.0 to 4.5 cm ³/10 min、2.2-4.2 cm³/10 min, or 2.8 to 4.0 cm ³/10 min, according to ASTM D1238-10. In one embodiment, the flame retardant polymer composition has a melt flow rate at 230℃in the range of 47-70 cm ³/10 min、49-67 cm³/10 min、52-65 cm³/10 min, or 55-62 cm ³/10 min, according to ASTM D1238-10.

In one embodiment, the flame retardant polymer composition has a tensile strength at break in the range of 6 to 10 MPa, or 6.5 to 9.5 MPa, or 7.0 to 9.0 MPa, according to ASTM D638-14. In one embodiment, the flame retardant polymer composition has a tensile strain at break in the range of 15 to 40%, 17 to 40%, 19 to 38%, 21 to 36%, or 23 to 35% according to ASTM D638-14.

The term "flame retardant" refers to any chemical that, when added to a polymer, can prevent, inhibit or delay the spread of a fire and/or limit damage caused by a fire. Flame retardants are activated by the presence of an ignition source and are intended to prevent or slow down further ignition development by a variety of different physical and chemical methods. The flame retardant may function by one or more of endothermic degradation, thermal shielding, dilution of the gas phase, and quenching of the gas phase free radicals. Flame retardants, which act by endothermic degradation, remove heat from the substrate and thus cool the material. Flame retardants that act through heat shielding create a thermal barrier between the positive and unburned portions of the material, such as by forming char that separates the flame from the material and slows down the transfer of heat to the unburned material. Flame retardants can function by dilution of the gas phase, generating inert gases (e.g., carbon dioxide and/or water) by thermal degradation, and thus diluting the combustible gas, thus reducing the partial pressure of the combustible gas and oxygen and slowing the reaction rate. In certain embodiments, the flame retardant used in the flame retardant polymer compositions disclosed herein functions by endothermic degradation and/or dilution of the gas phase. In one embodiment, the alkaline earth carbonate and/or magnesium hydroxide of the mineral blend reacts endothermically during combustion of the polymer below 600 ℃.

In one embodiment, the mineral blend may be considered to be expanded, meaning that it swells due to thermal exposure, thus increasing in volume and decreasing in density. Preferably, this density reduction limits any subsequent heat transfer. The expansion properties of the mineral blend may be a feature that imparts flame retardant behavior to the flame retardant polymer composition and may enable its use as a material for passive fire protection. In one embodiment, the flame retardant polymer composition has a UL94 flammability rating of V-0 and/or V-1. In one embodiment, a flame retardant polymer composition having dicumyl peroxide may be more flame resistant than a similar flame retardant polymer composition without dicumyl peroxide.

According to a second aspect, the present disclosure relates to an insulated wire product comprising a conductive wire coated with a layer of the flame retardant polymer composition of the first aspect. "conductive wire" as defined herein is a material having a resistivity of at most 10 ^-6 Ω -m, or at most 10 ^-7 Ω -m, or at most 10 ^-8 Ω at a temperature of 20-25 ℃. The conductive wire may comprise platinum-iridium alloy, iridium, titanium alloy, stainless steel, gold, cobalt alloy, copper, aluminum, tin, iron, and/or some other metal.

The thickness of the flame retardant polymer composition covering the wire may be, for example, equal to or less than about 1 mm a. For example, the thickness of the flame retardant polymer composition can be equal to or less than about 0.9 mm, or equal to or less than about 0.8 mm, or equal to or less than about 0.7 mm, or equal to or less than about 0.6 mm. The thickness of the flame retardant polymer composition covering the wire may be, for example, at least about 0.1 mm, or at least about 0.2 mm. The wire diameter may be in the range of 0.01 mm-3 cm, 0.1 mm-2 cm, 1.0 mm-1 cm, or 2.0 mm-5.0 mm.

According to a third aspect, the present disclosure relates to a method of preparing the flame retardant polymer composition of the first aspect. The method includes melt mixing a polysiloxane or fatty acid coated mineral blend with a polymer.

In one embodiment of the method, the polysiloxane or fatty acid coated mineral blend is present as particles having an average diameter in the range of 0.5-10 [ mu ] m, 0.8-9 [ mu ] m, 1-8 [ mu ] m, or 2-7 [ mu ] m. In one embodiment of the method, the BET surface area of the polysiloxane or fatty acid coated mineral blend is in the range of 2-20 m ²/g、4-17 m²/g、6-15 m²/g or 8-13 m ²/g.

In one embodiment of the process, melt mixing is performed in a single or twin screw extruder with an RPM in the range of 100-300, 120-280 or 140-260 and heating at a temperature gradient with a maximum temperature in the range of 150-250 ℃ or 160-240 ℃ and a minimum temperature in the range of 25-70 ℃, or 28-40 ℃, or about 30 ℃. In one embodiment, the RPM may be about 150 or about 250. In one embodiment, the maximum temperature may be about 170 ℃ or about 239 ℃. The total length of the screw extruder may be 0.5-3m, or 0.8-2m.

In one embodiment of the method, melt mixing comprises first melt mixing the polymer in a heated screw extruder, and then adding the mineral blend (with or without fatty acid and polysiloxane coating) to the heated screw extruder. In a further embodiment, the mineral blend may be added in two parts and at two different locations along the screw extruder, as indicated in fig. 2B. Preferably, the mineral blend is added through a hopper attached to the hammer mill and the mixture productivity of the hammer mill may be 500-900 kg/h or about 800 kg/h. In one embodiment, the feeder throughput of the mineral blend may be in the range of 5-25 kg/h, or 7-20 kg/h, or about 9-12 kg/h. In one embodiment, the flame retardant polymer composition may be produced at a rate of 1 to 2,000 kg/h, 10 to 1,000 kg/h, or 20 to 100 kg/h using a single extruder with one or two screws.

The flame retardant polymer composition may be prepared by compounding the polymer with a mineral blend and any optional additives. Compounding is a technique well known to those skilled in the art of polymer processing and manufacturing and consists of preparing plastic formulations by mixing and/or blending polymers and optionally additives in the molten state. It is understood in the art that compounding is different from blending or mixing processes that occur at temperatures below which the components become molten. For example, compounding may be used to form a masterbatch composition. Compounding may, for example, include adding the masterbatch composition to a polymer to form an additional polymer composition.

The flame retardant polymer composition described herein may, for example, be extruded. For example, compounding may be performed using a screw (e.g., twin screw), a compounder (e.g., a Baker Perkins 25 mm twin screw compounder). For example, compounding can be performed using a multi-roll mill (e.g., a two-roll mill). Compounding may be carried out using, for example, a co-kneader or an internal mixer. The methods disclosed herein may, for example, include compression molding or injection molding. The polymer and/or mineral blend and/or optional additives may be pre-mixed and fed from one or more hoppers. In one embodiment, grafted maleic anhydride polypropylene Irganox B215 (Irganox 1010/Irgafos 168) and silicone rubber sheets are added as additives, and the silicone rubber sheets may be impregnated with a mineral blend.

In one embodiment, the extruded molten flame retardant polymer composition may be in the form of pellets or strands. These may be cooled, for example in a water bath, and then granulated. After pelletization, the flame retardant polymer composition may be dried at 50-80℃or 70℃for 6-24 hours or 12 hours. The dried pellets of the flame retardant polymer composition may be calendered to form a sheet or film, or subjected to other molding or injection methods as described herein.

The flame retardant polymer composition described herein may be, for example, formed into a desired form or article. Shaping of the flame retardant polymer composition may, for example, include heating the composition to soften it. The polymer compositions described herein may be shaped, for example, by molding (e.g., compression molding, injection molding, stretch blow molding, injection blow molding, overmolding), extrusion, casting, or thermoforming.

The flame retardant polymer composition may be injection molded, blow molded, compression molded, low pressure injection molded, extruded and then thermoformed by male or female mold vacuum thermoforming, injection compression molding, injection foaming, injection slush molding, compression molding, or prepared by a mixing process (e.g., low pressure molding) wherein a covering layer of the flame retardant polymer composition, which is still molten, is placed on the back of the skin foam composite and pressed at low pressure to form a skin and bonded to a rigid substrate. For injection molding, the molding temperature may be in the range of about 150 ℃ to about 350 ℃, or about 170 ℃ to about 320 ℃; the injection pressure is typically in the range of about 5 to about 100MPa, or about 10 to about 80 MPa; and the mold temperature is typically in the range of about 20 ℃ to about 80 ℃, or about 20 ℃ to about 60 ℃. In other embodiments, the flame retardant polymer composition may be formed by other manufacturing methods, such as casting, molding, machining, or joining two or more parts.

In one embodiment, after injection molding or forming the flame retardant polymer composition, surface treatment methods may be applied, including but not limited to priming, solvent etching, sulfuric acid or chromic acid etching, sodium treatment, ozone treatment, flame treatment, UV irradiation, and plasma treatment.

According to a fourth aspect, the present disclosure is directed to a method of forming a flame retardant object. The method includes heating the flame retardant polymer composition of the first aspect to form a molten composition. The surface of the object is then contacted with the molten composition to form a flame retardant object. Or the molten flame retardant polymer composition from the extruder may be contacted with the object without cooling and pelletizing during melt mixing to form the flame retardant polymer composition. As used herein, a surface in contact with a molten composition is considered equivalent to a molten composition in contact with a surface.

In one embodiment of the method, the flame retardant object is an electrical conductor, an automotive part, a building material, an electronic device or an electrical appliance. The fire-retardant object may be a side wall, a door seal, an instrument panel, a portion of a marine or aircraft interior, a portion of furniture, a wall mount, an insulator, an electrical or electronic device housing, an electrical insulator, a door, a duct, a fire shield, a mat, a cable sheath, or some other object.

According to a fifth aspect, the present disclosure is directed to a method of forming a flame retardant object. The method includes injection molding the flame retardant polymer composition of the first aspect to form a flame retardant object. As previously mentioned, in some embodiments, injection molding may be performed directly from the melt-mixed polymer and mineral blend.

In one embodiment of the method, the flame retardant object may be any object as previously listed. In other embodiments, the object may be, for example, an elastic seal, an elastic bearing, a flexible sheet for waterproofing and/or heat insulation.

The following are exemplary embodiments of the present disclosure:

embodiment 1: a flame retardant polymer composition comprising:

a mineral blend comprising:

Kaolin;

Alkaline earth carbonates; and

Magnesium hydroxide; and

The polymer is used as a polymer of the polymer,

Wherein the mineral blend is present in a weight percentage in the range of 20 to 80 weight percent, and

Wherein the polymer is present in a weight percentage in the range of 20 to 80 weight percent, each relative to the total weight of the flame retardant polymer composition.

Embodiment 2: the flame retardant polymer composition of embodiment 1, wherein the mineral blend comprises

10-50% By weight of kaolin;

10-50 wt% alkaline earth carbonate; and

10-50 Wt% magnesium hydroxide, each relative to the total weight of the mineral blend.

Embodiment 3: the flame retardant polymer composition of embodiment 1 or 2, wherein the mineral blend is dispersed in the polymer.

Embodiment 4: the flame retardant polymer composition of any of embodiments 1-3, wherein the kaolin is natural kaolin.

Embodiment 5: the flame retardant polymer composition according to any of embodiments 1-4, wherein the alkaline earth carbonate is at least one selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, huntite and magnesite.

Embodiment 6: the flame retardant polymer composition of any of embodiments 1-5, wherein the polymer is a polyolefin.

Embodiment 7: the flame retardant polymer composition according to any of embodiments 1-6, wherein the polymer is an elastomer selected from the group consisting of acrylic rubber, ethylene propylene diene rubber, ethylene vinyl acetate, fluoroelastomers, polybutadiene, polyisobutylene, polyisoprene, silicone rubber, and natural rubber.

Embodiment 8: the flame retardant polymer composition of any of embodiments 1-6, wherein the polymer is a thermoplastic polymer selected from the group consisting of acrylic, acrylonitrile butadiene styrene, ethylene vinyl acetate, nylon, poly (vinyl acetate), polyacrylonitrile, polybenzimidazole, polybenzoxazole, polybenzothiazole, polybutene-1, polybutene, polycarbonate, polyethersulfone, polyetheretherketone, polyetherimide, polyethylene adipate, polyethylene terephthalate, polyimide, polylactic acid, polymethyl acrylate, polymethyl methacrylate, polymethylpentene, polyoxymethylene, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, polytetrafluoroethylene, polyvinyl alcohol, polyvinyl chloride, polyvinyl ester, and polyvinylidene fluoride.

Embodiment 9: the flame retardant polymer composition of embodiment 8 wherein the thermoplastic polymer comprises ethylene vinyl acetate and polyethylene.

Embodiment 10: the flame retardant polymer composition of embodiment 9 wherein the polyethylene is a linear low density polyethylene.

Embodiment 11: the flame retardant polymer composition of any one of embodiments 1-10, further comprising less than 5 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

Embodiment 12: the flame retardant polymer composition of embodiment 11 comprising less than 0.1 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

Embodiment 13: the flame retardant polymer composition of any of embodiments 1-12, substantially free of halogen.

Embodiment 14: the flame retardant polymer composition of any one of embodiments 1-13, further comprising titanium dioxide.

Embodiment 15: the flame retardant polymer composition of any one of embodiments 1-14, further comprising 0.01-5 weight percent fatty acid, polysiloxane, or both, each relative to the total weight of the flame retardant polymer composition.

Embodiment 15A: the flame retardant polymer composition of any one of embodiments 1-14, wherein the kaolin is surface treated with a surface treating agent, and the surface treating agent is present in an amount of up to about 5 weight percent, based on the total weight of the kaolin (or particulate mineral).

Embodiment 16: the flame retardant polymer composition of embodiment 15, wherein the fatty acid is stearin and the polysiloxane is PDMS.

Embodiment 17: the flame retardant polymer composition of embodiment 15 or 16 comprising both fatty acid and polysiloxane in a weight ratio of stearin to polysiloxane range of 1:1 to 6:1.

Embodiment 18: the flame retardant polymer composition of any one of embodiments 1-17, further comprising 0.01-0.05 weight percent dicumyl peroxide, relative to the total weight of the flame retardant polymer composition.

Embodiment 19: the flame retardant polymer composition of any of embodiments 1-18 having a density in the range of 1.1-1.8 g/cm ³.

Embodiment 20: the flame retardant polymer composition of any of embodiments 1-19 having a melt flow rate in the range of 2.0 to 4.5 cm ³/10 min at 150 ℃ according to ASTM D1238-10.

Embodiment 21: the flame retardant polymer composition of any of embodiments 1-20 having a melt flow rate in the range of 47-70 cm ³/10 min at 230 ℃ according to ASTM D1238-10.

Embodiment 22: the flame retardant polymer composition of any of embodiments 1-21 having a tensile strength at break according to ASTM D638-14 in the range of 6-10 MPa.

Embodiment 23: the flame retardant polymer composition of any of embodiments 1-22 having a tensile strain at break according to ASTM D638-14 in the range of 15-40%.

Embodiment 24: the flame retardant polymer composition of any of embodiments 1-23 having a UL94 flammability rating of V-0 or V-1.

Embodiment 25: an insulated wire product comprising: a conductive wire coated with a layer of the flame retardant polymer composition of any of embodiments 1-24.

Embodiment 26: a method of preparing the flame retardant polymer composition of any of embodiments 1-15 and 16-24, the method comprising: a polysiloxane or fatty acid coated mineral blend is melt mixed with the polymer.

Embodiment 26A: a method of preparing the flame retardant polymer composition of embodiment 15A, the method comprising: a polysiloxane or fatty acid coated mineral blend is melt mixed with the polymer.

Embodiment 27: the method of embodiment 26, wherein the polysiloxane or fatty acid coated mineral blend has an average diameter in the range of 0.5 to 10 μm.

Embodiment 28: the method of embodiment 26 or 27, wherein the polysiloxane or fatty acid coated mineral blend has a BET surface area in the range of 2-20 m ²/g.

Embodiment 29: the method of any of embodiments 26-28, wherein the melt mixing is performed in a screw extruder having an RPM in the range of 100-300 and heating at a temperature gradient having a maximum temperature in the range of 150-250 ℃.

Embodiment 30: the method of any of embodiments 26-29, wherein the melt mixing comprises first melt mixing the polymer in a heated screw extruder and then adding the mineral blend to the heated screw extruder.

Embodiment 31: a method of forming a flame retardant object, the method comprising:

Heating the flame retardant polymer composition of any of embodiments 1-24 to form a molten composition; and

Contacting a surface of an object with the molten composition to form a flame retardant object.

Embodiment 32: the method of embodiment 31, wherein the object is an electrical conductor, an automotive part, a building material, an electronic device, or an electrical appliance.

Embodiment 33: a method of forming a flame retardant object, the method comprising:

The flame retardant polymer composition of any of embodiments 1-24 is injection molded to form a flame retardant object.

Embodiment 34: the method of embodiment 33, wherein the flame retardant object forms an outer shell or surface of an electrical conductor, an automotive part, a building material, an electronic device, or an electrical appliance.

The following examples are intended to further illustrate the schemes for preparing, characterizing, and using flame retardant polymer compositions and are not intended to limit the scope of the claims.

Example 1

Purpose(s)

The object of the present invention is to develop a flame retardant mineral solution capable of at least partially replacing aluminium hydroxide (ATH) in polyolefin compounds for wire and cable applications, more particularly for covering and isolating composites of low voltage wires and cables. Four different minerals are considered.

Magnesium Hydroxide (MH) provides the compound with self-extinguishing capability due to the endothermic process of thermal decomposition of hydroxyl groups into vapors, which reduces the O ₂ concentration and combustible gases on the surface of the polymer sheet, thus reducing the burn rate.

The hydroxide kaolin or calcined kaolin has a layered structure that reduces the permeability of combustible gases through the polymer matrix. Kaolin also has a positive effect on char skin formation that provides thermal insulation. See m. Batistella et al Polymer Degradation and Stability 100 (2014) 54-62. "Fire retardancy of ethylene vinyl acetate/ultrafine kaolinite composites",, which is incorporated herein by reference in its entirety.

Calcium Carbonate (GCC) can have an expansion characteristic and can positively influence char skin formation when CaCO ₃ is applied with fatty acids and in the polymer matrix, which produces organic acids during the combustion process. See s.bellayer et al Polymer Degradation and Stability 94 (2009) 797-803. "Mechanism of intumescence of a polyethylene/calcium carbonate/stearic acid system" and a.lundgren et al Journal of Fire Sciences 2007, 25, 287. "Influence of the Structure of Acrylate Groups on the Flame Retardant Behavior of Ethylene Acrylate Copolymer Modified with Chalk and Silicone Elastomer",, each of which is incorporated herein by reference in its entirety.

Titanium dioxide acts as a white pigment to adjust the color properties.

Fatty acids are widely used coating agents and, when mixed with molten thermoplastics, can significantly improve the dispersibility and flowability of mineral products, see s.belayer et al (2009) and a.lundgren et al, each of which is incorporated herein by reference in its entirety.

The prototype development phase has three phases, each with different experimental designs to study different assumptions, but produces the evolution of the final prototype one after the other.

In stage 1, two process variables (screw speed and temperature profile) and three different flame retardant additives Hydral 710,710 (ATH) and two prototypes (FRM 012017 and FRM 022017) were studied based on a ternary blend of kaolin, magnesium hydroxide and calcium carbonate.

In stage 2, stage 1 was studied based on the same ternary blend for the same process variables and three different flame retardants Hydral 710,710 (ATH) and two prototypes (FRM 022017 and FRM 062017), but the particle size distribution was different between them.

In stage 3, the effect of small amounts of dicumyl peroxide on the flame retardancy of the compound produced by prototype FRM 062017 in the stage 2 structure was studied. See l. Zhang et al J Mater Sci (2007) 42:4227-4232. "Aluminum hydroxide filled ethylene vinyl acetate (EVA) composites: effect of the interfacial compatibilizer and the particle size",, incorporated herein by reference in its entirety.

After finding the phase sequence of the solution, it was concluded that prototype FRM 062017 reached a flame retardancy result of V0 in the vertical UL94 method and that there was no statistical difference in mechanical properties between Hydral and 710 (ATH) when it was combined with a small amount of dicumyl peroxide. This prototype allows the production of polymers with a generally higher temperature profile (up to 200 ℃ melt polymer compound) and screw speed than ATH compounds, resulting in an improvement of surface roughness and extrudability in single screw extruders. Each stage will be described and reviewed in detail.

The purpose is as follows: engineering mineral solutions were developed to at least partially replace aluminum hydroxide (Martinal OL104 and Apyral 60 CD) in PE/EVA compounds that were used to isolate and cover low voltage cables and wires. This will focus on developing engineered mineral solutions that are capable of maintaining flame retardant, mechanical, thermal and electrical properties, as determined by the standard ABNT NBR 13248-15 for wire and cable assemblies. In addition, by increasing the temperature distribution and screw speed, the smoothness of the cable surface is maintained and the processability of the polyolefin compound is improved to achieve better output performance, as compared to conventional materials.

Example 2

Stage 1-study of prototype 012017 and prototype 022017

In view of the above concepts, four minerals were chosen, two kaolins, one GCC and one MH, which were put together to have synergistic properties in the polyolefin compound when coated with fatty acids. They were chosen for their particle size distribution (kaolin and GCC) and both kaolins were chosen to understand whether calcination gave some final distinction and MH was the only choice of the feedstock. The hydrous kaolin used has a shape factor of less than 7. All prototypes were produced by standard conditions currently used for coating materials. Table 1 shows the relevant physical and chemical results of this study.

TABLE 1 mineral prototype formulation and physical-chemical results

Material	Hydral 710	Hydrous kaolin	Calcined kaolin	GCC	Magnesium hydroxide	Prototype 012017	Prototype 022017
								Aluminum hydroxide (ATH)	100%	-	-	-	-	-	-
Hydrous kaolin	-	100%	-	-	-	-	32.15%
								Ground calcium carbonate	-	-	-	100%	-	32.15%	32.15%
Magnesium hydroxide	-	-	-	-	100%	32.15%	32.15%
								Calcined kaolin	-	-	100%	-	-	32.15%	-
Fatty acid	-	-	-	-	-	1.08%	1.08%
								Irganox 1010	-	-	-	-	-	0.002%	0.002%
Silicone oil (350 Cps)	-	-	-	-	-	0.49%	0.49%
								Titanium dioxide (Tiona RKB 2)	-	-	-	-	-	1.97%	1.97%
PSD_{Laser diffraction}-D₁₀ (µm)	0.65	0.53	0.76	0.68	1.15	0.62	0.49
								PSD_{Laser diffraction}-D₅₀ (µm)	1.75	1.41	2.35	2.20	7.17	2.84	2.49
PSD_{Laser diffraction}-D₉₉ (µm)	5.04	7.29	19.64	11.82	23.56	22.68	21.78
								PSD_{Laser diffraction}-D_{Average of}(µm)	1.94	1.83	3.94	3.25	8.10	4.87	4.52
Linseed oil absorption (g/100 g)	30.0	49.6	88.1	20.9	26.0	30.7	26.9
								Moisture (%)	0.30	5.04	0.65	0.30	0.50	0.40	0.4
Loss on ignition (%)	31.27	13.10	0.25	42.40	28.14	23.59	27.82
								Conductivity ([ mu ] S/cm)	65.74	340.0	61.46	84.0	108.5	79.76	193.4
Bulk Density (g/cm current)	0.42	1.00	0.31	0.83	0.74	0.54	0.54
								B.E.T (m²/g)	3.1	10.7	14.1	3.0	8.2	7.5	6.0

The compounding process was carried out by the compositions shown in tables 2 and 3. Ten experiments were performed according to the design of experiments (DoE) and formulation reference plan. Two experiments were conducted using ATH reference under two conditions of screw speed, while 8 experiments involved varying two screw speeds, two temperature profiles and two prototypes (kaolin, GCC and MH). The actual variables used in the twin screw extruder are shown below and describe how these variables are set.

Table 2-formulation reference.

Material	Reference (wt.%)	Prototype 01 (wt.%)	Prototype 02 (wt.%)
				EVA Braskem HM728	12.1	12.1	12.1
LLDPE Braskem LH218	24.5	24.5	24.5
				Bluesil MF 175	1.5	1.5	1.5
Polybond 3200	1.5	1.5	1.5
				Irganox B215	0.4	0.4	0.4
Hydral 710	60.0	-	-
				Prototype 012017	-	60.0	-
Prototype 022017	-	-	60.0
				Totals to	100.0	100.0	100.0

TABLE 3 prototype 012017 x prototype 022017 DoE (orthogonal matrix)

The variables and their levels are listed below:

1. delta of screw speed:

a. Δ=0 (-1)

b. Δ≠0 (+1)

The first screw speed level (Δ=0) is the rotation necessary to produce a compound of load Hydral (ATH) under stable conditions, such as low torque and low melting temperature (Tm). However, the second level (Δ+.0) is the rotation necessary to produce the reference compound (Hydral 710) under stable conditions but at the torque limit of the extruder and the maximum melting temperature of 170 ℃.

For example, if the screw speed is set at 300 rpm to produce a reference compound at low torque and low temperature Tm, it will be considered as Δ=0 (-1). And, if the screw speed is set at 400 rpm to produce a reference compound at the limit torque of the extruder and tm=170 ℃, it will be considered as Δ=100 (+1).

2. Temperature distribution coefficient:

a. 28 (-1)

b. 56 (+1)

A logarithmic equation is presented to describe the temperature profile to be applied in a twin screw extruder. The mathematical method is used to reduce the number of variables from 9 or 10 to 1, which is represented by the angular coefficient of the equation [ ŷ =k×ln (x) +b ]. Fig. 1 shows a graphical representation of the curve.

3. Flame retardant prototype

A. prototype 012017

B. Prototype 022017

The experimental design was performed using a ZE 25A x 46D UTXi Berstorff twin screw extruder. Fig. 2A and 2B show schematic views of a twin screw extruder. Due to the amount of Flame Retardant (FR) mineral, the feeding procedure of the Flame Retardant (FR) into the extruder must be split. The average feeder independently receives the preblend (Bluesil MF and EVA), other preblends (Irganox B215 and Polybond 3200) and LLDPE through the screw feeder. The two side feeders only received FR minerals, which were separated at a ratio of 3:1 to ensure dispersion and prevent mineral clogging, with an extruder throughput of 10 kg/hr. The first side feeder in zone 3 received 45 wt% (from 60 wt%) and the second side feeder in zone 5 received 15 wt% (from 60 wt%). Table 4 shows the actual temperature profile adjusted by the extruder and table 5 shows the actual variables set for the experiments performed.

TABLE 4 set point for temperature distribution

Extruder zone	Low temperature distribution	High temperature distribution
			Zone 1 (. Degree. C.)	30	30
Zone 2 (. Degree. C.)	100	100
			Zone 3 (. Degree. C.)	119	139
Zone 4 (. Degree. C.)	139	178
			Zone 5 (. Degree. C.)	150	200
Zone 6 (. Degree. C.)	158	216
			Zone 7 (. Degree. C.)	164	229
Zone 8 (. Degree. C.)	170	239
			Region 12	170	239
Zone 13 die (. Degree. C.)	170	239

TABLE 5 design of experimental practical conditions

The feeder throughput in zone 3 (figure 3) has different results compared to ATH and prototype, which are related to the bulk density observed in mineral compositions. The coating solution also plays an important role in the flowability of the mineral composition. Considering that the feeder throughput in zone 3 is directly related to extruder productivity, during the test, 20 kg/hr would be possible for the prototype, but the study was comparative in that all materials were produced by the same conditions of throughput 10 kg/hr.

From 10 experiments, only 3 were not possible due to the excessive generation of bubbles and holes; these samples were Hydral 710,710 (ATH) (250 RPM and low temperature) and prototype 012017 (high temperature 150 and 250 RPM). Other compounds have good processability under the DoE setting conditions.

The process results show that under the same extrusion conditions, the FR prototype produced less torque and die pressure than ATH during compounding, as shown in fig. 4A and 4B, this effect is related to the viscosity of the compound, which is affected by filler loading, surface area and temperature. Note that the densities of the compounds as shown in fig. 5 are comparable, proving that the side feeder works well. Even prototypes have a larger surface area and show lower compound viscosity due to the different interactions between the coating particles and the polymer. Another reason for the reduced viscosity is the increased temperature, which is only applicable to prototypes, since they are more stable than ATH at higher temperatures and screw speeds. Melt Flow Rate (MFR) was measured at 21.6 kg at both 150 ℃ and 230 ℃ temperature conditions to understand the difference in flow properties during the process. See ASTM D 1238 – 10: Standard Test Method for Melt flow Rates of Thermoplastics by Extrusion Plastometer,, which is incorporated by reference herein in its entirety. Fig. 6A and 6B show melt flow rate MFR results.

All compounds were characterized by flame retardancy (vertical UL94 method), mechanical properties (ASTM D638, die IV) and MFR. See ASTM D 1238 - 10: Standard Test Method for Melt flow Rates of Thermoplastics by Extrusion Plastometer; UL94 - Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances; and ASTM D638-14: STANDARD TEST Method for Tensile Properties of Plastics, each of which is incorporated herein by reference in its entirety.

In addition, the roughness index is determined taking into account the tactile and visual observation of the extruded "spaghetti". The test specimens for UL94 and tensile strength and strain at break properties were molded by a roller mill at 125 ℃ to plasticize the pellets and the board was molded in a hot press, wherein the sample was left at 150 ℃ for 2 minutes and at ambient temperature for 3 minutes, with a nominal pressure of 37 kgf/cm ².

Interesting results were observed for prototype 022017, which reached V0 and had the best roughness index when the material was fed out in a twin screw extruder with a high temperature profile and 250 RPM. Table 6 shows UL94 and roughness index of all compounds produced. In the prototype 022017 loaded compounds, it was observed that when materials were processed at high temperatures of 250 RPM, their roughness index was reduced, and thus this effect might be related to the plasticizing behavior of the prototype compound. The results of the tensile strength properties of the prototypes shown in fig. 7A and 7B under different process conditions demonstrate that the average and distribution particle size of the prototypes is slightly worse than the ATH-loaded compounds, as the prototypes are higher and wider than the ATH. Furthermore, the mechanical properties of the compound carrying prototype 022017 were independent of temperature distribution (high and low) and screw speed (150 and 250 RPM).

TABLE 6 UL94 and roughness index results

1-Roughness index (visual observation and touch) 5 is the coarsest, while 1 is the least coarse.

Example 3

Stage 2-CCDM external experiment

Prototype 022017 had acceptable flame retardancy and roughness index properties when processed through a twin screw extruder under two process conditions (high temperature; high speed and low temperature; low speed). Thus, the project continues to upgrade prototype 022017, decreasing the average particle size and narrowing the particle size distribution. First, MH was ground by a reverse jet mill and, second, the kaolin and GCC grades were changed. Prototype 062017 incorporates all modifications made in the mineral matrix and it proceeds through standard conditions currently used for coating materials. Table 7 shows the relevant physical and chemical results for each material used for the study.

TABLE 7 mineral prototype formulation and physical-chemical results

Material	Hydral 710	Containing water	GCC	Magnesium hydroxide	Prototype 062017
						Aluminum hydroxide (ATH)	100%	-	-	-	-
Hydrous kaolin	-	100%	-	-	32.15%
						Ground calcium carbonate	-	-	100%	-	32.15%
Magnesium hydroxide	-	-	-	100%	32.15%
						Fatty acid	-	-	-	-	1.08%
Irganox 1010	-	-	-	-	0.002%
						Silicone oil (350 Cps)	-	-	-	-	0.49%
Titanium dioxide (Tiona RKB 2)	-	-	-	-	1.97%
						PSD_{Laser diffraction}-D₁₀ (µm)	0.65	0.56	0.62	0.79	0.57
PSD_{Laser diffraction}-D₅₀ (µm)	1.75	1.87	2.60	2.47	2.26
						PSD_{Laser diffraction}-D₉₉ (µm)	5.04	7.76	17.05	7.63	11.17
PSD_{Laser diffraction}-D_{Average of}(µm)	1.94	2.37	4.11	2.80	2.96
						Linseed oil absorption (g/100 g)	30.0	38.2	17.3	30.7	18.2
Moisture (%)	0.30	4.17	0.3	1.18	0.6
						Loss on ignition (%)	31.27	12.91	41.98	28.45	28.43
Conductivity ([ mu ] S/cm)	65.74	392.7	100.7	221.7	164.7
						Bulk Density (g/cm current)	0.42	1.06	0.91	0.62	0.77
B.E.T (m²/g)	3.1	16.5	2.9	10.5	8.3

The compounds of load prototypes 022017 and 062017 were prepared in a twin screw extruder "COPERION" (diameter 35 mm and L/D44) for compounding under two different process conditions (high temperature; high speed and low temperature; low speed), which achieved better flame retardant results. In the first study ATH was produced under the same conditions (low temperature; low speed). Formulation references were unchanged and were used as in the same batch of the first study. Since the present extruder produces more shear, new parameters must be set for the screw speed, but the temperature profile remains the same as in the first study. Table 8 shows the set points of the temperature profile and table 9 shows the experimental design under actual process conditions.

TABLE 8 set point for temperature distribution

Extruder zone	Low temperature distribution	High temperature distribution
			Zone 1 (. Degree. C.)	40	40
Zone 2 (. Degree. C.)	100	100
			Zone 3 (. Degree. C.)	119	139
Zone 4 (. Degree. C.)	131	162
			Zone 5 (. Degree. C.)	145	178
Zone 6 (. Degree. C.)	150	190
			Zone 7 (. Degree. C.)	154	200
Zone 8 (. Degree. C.)	158	209
			Zone 9 (. Degree. C.)	162	216
Region 10 (. Degree. C.)	164	223
			Die head (DEG C)	167	229

TABLE 9 design of experimental practical conditions

FR mineral is fed from a side feeder located in zone 6 and as a result, the fluidity of the mineral is important to determine the throughput of the extruder. Note that in fig. 8, the feeder throughput for the three FR minerals and prototype 062017 used in the study had better flow properties than the other FR minerals due to the presence of the hydrophobic coating. However, the prototype compound was produced at a constant 10 kg/hr extruder output.

The extruder of CCDM has no torque controller in its CLP, but may employ an amperage of the extruder engine that varies proportionally as the material flow resistance varies. Even though the surface area variation between prototypes is not the average factor affecting the extruder amperage, in fact, the temperature profile is the average factor affecting this variable, as can be observed in fig. 9A. As seen in the first study, ATH compounds had lower MFR than the prototype compounds. Comparing prototype compounds with each other, it can be seen that compounds produced by higher conditions exhibited higher MFR results, as noted in fig. 9B.

After compounding, sheets were produced by CCDM using a single screw extruder Miotto EM 03/45E (diameter 45 mm and L/D25) and evaluated for method and roughness performance. It is noted in table 10 that the die pressure was fixed to understand the behavior of the extruder during extrusion of those different materials. The compounds produced by twin screw extruders at higher temperature and speed showed better performance in terms of the method and roughness of the sheets produced by single screw extruders. Thus, the compound can be molded at high speed (higher shear heating). The observed effects are related to their process history in terms of plasticization and polymer-particle wettability.

TABLE 10 Single screw extruder results

All compounds were characterized in terms of flame retardancy (vertical UL94 method), mechanical properties (ASTM D638, die IV) and MFR. See ASTM D1238-10, UL94; and ASTM D, each incorporated herein by reference in its entirety. In addition, the roughness index is determined taking into account the tactile and visual observation of the sheet extruded through the single screw extruder. The test specimens for UL94 and tensile strength and strain at break properties were molded by a roller mill at 125 ℃ to plasticize the tray, and the board was molded in a hot press, with the sample resting at 150 ℃ for 2 minutes and at ambient temperature for 3 minutes, nominal pressure 37 kgf/cm ².

The history in twin screw extruders has an important impact on mechanical properties (especially tensile strain at break that can be observed in fig. 10A and 10B), their strain results are higher when prototypes are produced under higher process conditions, and they show better performance than ATH-loaded compounds. However, there was no statistical difference in tensile strength at break between the compounds carrying prototype 062017 and ATH, which is the effect caused by the deliberate reduction of PSD in prototype 062017 relative to prototype 022017 which has slightly worse performance than ATH.

The particle size distribution significantly affects the flame retardancy. As shown in table 10, prototype 062017 had better performance than prototype 022017 when compared under both method conditions. However, prototype 022017 reduced its performance when compared and this may be caused by the shear rate differences between the extruders used, reducing some properties of the polymer matrix such as chain length (molar weight). Furthermore, PSD may be the second averaging factor for the reduction in flame retardant performance of prototype 022017, but in prototype 062017, even an almost 5 wt% reduction in the concentration of FR minerals on the order of magnitude gives better results when compared in both studies, as occurs in prototype 022017. Table 11 shows the flame retardance, density and mineral content in the compounds.

TABLE 11 results of Compounds

Example 4

Stage 3-additives to improve flame retardant properties

Organic peroxides have been found as a solution to improve flame retardant properties. See Zhang et al, which is incorporated herein by reference in its entirety. It was noted that the addition of 0.03% by weight of dicumyl peroxide (DCP) to the prototype 062017-loaded compound improved flame retardancy and maintained mechanical properties in terms of performance. DCP was added by roller mill at 125℃over 1 minute and then molded by hot press, wherein the compound sheet was left at 150℃for 2 minutes and then at ambient temperature for 3 minutes, nominal pressure 37 kgf/cm ². Table 12 shows the flame retardant results for each compound with and without DCP. Fig. 10A and 10B show tensile strength at break and tensile strain at break. Fig. 12 shows a photograph of a sample after a combustion test, which test can observe that the DCP-containing supported prototype 062017 compound has a dense char skin compared to the additive-free compound, which may be the reason for achieving better results in DCP-loaded materials.

Table 12-flame retardant results.

In view of the above examples, mineral solutions were developed to at least partially replace ATH for wire and cable insulation and covering compound flame retardance, and to maintain all properties evaluated in the study, with no statistical differences between the reference and mineral solutions.

It is noted that the formulation used as reference can be changed, the EVA polymer changed to another polymer with a higher MFI (higher molecular weight), the polymer matrix of the polymer graphitized with maleic anhydride changed from PP to LLDPE, and the amount increased from 1.5 wt% to 3 wt%. Those variations listed above can improve the level of mechanical properties and ensure constant flame retardant results.

During both stage 1 and stage 2 studies, plasticization of the compound during compounding in a twin screw extruder was observed to be strongly disturbed in the molding of the single screw extruder and in the overall properties of the compound carrying the prototype. Therefore, the temperature profile and screw speed must be adjusted. It can be manufactured by consumers where FR compounds will be produced because the differences associated with changing twin screw extruders (such as screw profile, shear heating, amount and location of side feeder, controller and extruder dimensions) can interfere with FR compound performance.

Prototype 012017 performs technical verification of wire and cable based crosslinked EPR and EPDM, and can replace 100% ATH and silanized calcined kaolin. As a result, all properties remain compliant with the cable specifications and standards.

Certain other tests are envisaged. Thermogravimetric analysis is a potential technique to determine the activation energy of a pyrolysis reaction of a material, considering that it is a first order reaction, and therefore has data from four curves for different heating rates for each sample. It will be able to fit the straight line of Arrhenius law and thus determine the activation energy of each material. Thus, when changing the particle size distribution and the presence of dicumyl peroxide, and comparing ATH compound references to prototype compounds, it will allow an understanding of the differences in thermal stability behavior during the heating process of the prototype-carrying compound. The method based on ASTM D1641 has a wide range of uses in research to compare thermal stability under an oxidant atmosphere or between different antioxidants, other uses being for comparing different flame retardant additives, measuring the rate of thermal decomposition that can hinder the combustion of a material. See ASTM D 1641 - 16: Standard Test Method for Decomposition Kinects by Thermogravimetric Using the Ozawa/Flynn/Wall Method,, which is incorporated by reference herein in its entirety.

Example 5

This example focused on developing an engineered mineral solution that is capable of maintaining flame retardant, mechanical, thermal and electrical properties, as determined by the standard ABNT NBR 13248-15 for assembled wires and cables. The formulation is adjusted in order to maintain the cable surface smooth and improve polyolefin processability by increasing the temperature profile and screw speed compared to conventional ATH materials.

As summarized below, this example analyzes the effect of changing materials and formulation methods: (1) Reducing the Particle Size Distribution (PSD) of the hydrous kaolin and alkaline earth carbonate; (2) From (i) applying fatty acids to all minerals to (ii) applying aminosilanes only to hydrous kaolin (to maximize alkaline sites in the mineral surface); and (3) adding a silica gel flame retardant additive to enhance performance during vertical combustion.

Prototype formulation

TABLE 13 mineral prototype formulation and physical-chemical results

As shown in table 13, formulation 12 and formulation 14 did not include fatty acid treatment of hydrous kaolin, dolomite or MDH. The uncoated particles will exhibit a smaller particle size distribution than the corresponding coated particles. The hydrous kaolin of formulations FRM 12 and FRM 14 was treated with an aminosilane coupling agent (γ -aminopropyl triethoxysilane), while dolomite and MDH were untreated. Formulation FRM 14 includes 1% silica gel to act as an additional flame retardant.

Compound formulation

Table 14-formulation reference.

The compounds for analysis were produced by pre-blending, dispersing, homogenizing by a roll mill and molding the sheet. The compound components are pre-blended by a physical mixture of powders and pellets. The dispersion was carried out in a laboratory-scale torque rheometer mixer (Thermo SCIENTIFIC HAAKE Banbury) using a thermoplastic rotor at a temperature of 150 ℃ and a speed of 60 RPM. Homogenization was performed on a laboratory scale roller mill for 2 minutes at a process temperature of 125 ℃. The sheet was molded at 150℃for 2 minutes and at 25℃for 3 minutes by a hot press at a pressure of 37kgf/cm ² (cooled with water).

The following mineral properties were evaluated: particle Size Distribution (PSD) (measured by laser diffraction), oil absorption, b.e.t. surface area, moisture and loss on ignition, conductivity, and bulk density. The compound properties evaluated include flammability (according to UL 94), mechanical properties (according to ASTM D638 die type IV), gloss (after molding in a two-roll mill) (to evaluate surface properties; torque x time and temperature (evaluated with an internal mixer), appearance and gloss (measured after a single screw extruder).

Evaluation of the compound produced with FRM 08 showed low surface quality during extrusion in a laboratory scale single screw extruder. Further testing was performed with a formulation having hydrous kaolin and diatomaceous earth (ground calcium carbonate), with a particle size distribution having a smaller D99 fraction (measured by laser diffraction). Table 15 presents some physical properties of the mineral raw material and table 16 shows prototype formulation properties.

TABLE 15 physical Properties of the raw materials

Material	Apyral 40CD	Paraglaze kaolin	Amazon Plus kaolin	Amazon plus+1% aminosilane kaolin	Micron 1/9CD GCC	Micron 1/2CD GCC	Itamag 150(2.5 µm)MDH
								Aluminum hydroxide (ATH)	100%	-	-	-	-	-	-
Hydrous kaolin	-	100%	100%	100%	-	-	-
								Ground calcium carbonate	-	-	-	-	100%	100%	-
Magnesium hydroxide	-	-	-	-	-	-	100%
								PSD- D₁₀ (µm)	0.61	0.56	0.10	0.61	0.62	0.40	0.79
PSD-D₅₀ (µm)	1.39	1.87	0.45	1.54	2.60	1.47	2.47
								PSD-D₉₉ (µm)	4.57	7.76	2.12	6.93	17.05	7.21	7.63
PSD-D_{Average of}(µm)	1.60	2.37	0.58	1.93	4.11	1.88	2.80
								Linseed oil absorption (g/100 g)	30.0	38.2	47.5	46.4	17.3	22.6	30.7
Moisture (%)	0.30	4.17	0.39	0.32	0.3	0.50	1.18
								Loss on ignition (%)	31.27	12.91	13.72	13.75	41.98	40.98	28.45

TABLE 16 physical Properties of formulations

Material	Apyral 40CD	FRM 08	FRM 11	FRM 12	FRM 14
						PSD- D₁₀ (µm)	0.61	0.45	0.37	0.46	0.58
PSD-D₅₀ (µm)	1.39	2.12	1.61	1.53	1.80
						PSD-D₉₉ (µm)	4.57	11.25	6.16	6.17	6.97
PSD-D_{Average of}(µm)	1.60	2.80	1.96	1.93	2.14
						Linseed oil absorption (g/100 g)	30.0	18.20	19.10	25.50	26.40
Moisture (%)	0.30	0.20	0.15	0.56	0.33
						Loss on ignition (%)	31.27	27.39	27.93	24.73	26.92
Conductivity ([ mu ] S/cm)	65.74	310.7	193.0	548.5	591.0
						Bulk Density (g/cm current)	0.42	0.59	0.34	0.41	0.39

The Particle Size Distribution (PSD) reported in table 15 and table 16 was measured by laser diffraction. They were measured before coating formulation FRM 08 with fatty acids, as the hydrophobic nature of fatty acids would interfere with laser diffraction techniques. Fatty acid coatings can increase particle size, resulting in poor surface quality and lower gloss.

Formulations FRM 08, FRM 11, FRM 12 and FRM 14 showed oil absorption rates lower than the absorption rate of 30g/100g of the tested aluminum hydroxide (ATH). These oil absorption rates correspond to acceptable processing capacities, indicating that formulations FRM 08, FRM 11, FRM 12 and FRM 14 may replace ATH or MDH in some applications. This in turn may save costs. Formulations FRM 08, FRM 11, FRM 12 and FRM 14 may also allow for higher processing temperatures to be used.

To investigate the effect of particle size distribution on surface irregularities of extrusion molded polymers, one sheet of each compound was molded, and the gloss was measured from both sides of the sheet at angles of 20 ° and 60 ° by a gloss meter apparatus. The two angles are measured considering the inside and outside of the sheet, so that the effect of composition variations on surface quality can be identified while excluding disturbances from the process variables. This may be related to the performance of the extruder equipment. Figures 13 and 14 present the results for the 20 ° and 60 ° angles of the polymer compound.

As shown in fig. 13 and 14, formulations FRM 12 and FRM 14 exhibited the highest gloss values. Both formulations included lower particle size hydrous kaolin treated with an aminosilane coupling agent and untreated dolomite and MDH. The particles of both formulations were not coated with fatty acids, so that the particle size of dolomite (GCC) and MDH remained unchanged. The use of formulations with smaller particle size hydrous kaolin and dolomite and without fatty acid resulted in fewer surface defects observed. Without being bound by theory, the fatty acid coating may lubricate the polymer compound surface, reducing the gloss performance. Coating of hydrous kaolin with aminosilanes results in improved gloss properties. Despite the presence of silica gel to act as a flame retardant, formulation FRM 14 exhibits a higher gloss.

As shown in fig. 13 and 14, formulations FRM 08 and FRM 11 exhibited higher gloss values than the ATH tested. Both formulations included hydrous kaolin, dolomite and MDH. However, as summarized in tables 14 and 15, formulation FRM 11 has lower hydrous kaolin and dolomite D10, D50 and D99 particle size distributions than FRM 08. Formulation FRM 11 exhibited a higher gloss value than FR 08. Without being limited by theory, smaller particle size distribution may improve the gloss performance and surface quality of fatty acid coated formulations.

Claims

1. A flame retardant polymer composition comprising:

a mineral blend comprising:

10-50% by weight of kaolin;

10-50 wt% alkaline earth carbonate; and

10-50 Wt% magnesium hydroxide, each relative to the total weight of the mineral blend; and

A polymer, and

0.01 To 5wt% of a fatty acid, a polysiloxane, or both, each relative to the total weight of the flame retardant polymer composition,

Wherein the mineral blend is present in a weight percentage in the range of 20-80 wt%,

Wherein the polymer is present in a weight percentage ranging from 20 to 80 weight percent, each relative to the total weight of the flame retardant polymer composition, and

Wherein the fatty acid and/or polysiloxane is coated onto the surface of the mineral blend.

2. The flame retardant polymer composition of claim 1, wherein the mineral blend is dispersed in the polymer.

3. The flame retardant polymer composition of claim 1, wherein the kaolin is natural kaolin.

4. The flame retardant polymer composition according to claim 1, wherein the alkaline earth carbonate is at least one selected from the group consisting of calcium carbonate, magnesium carbonate, dolomite, huntite and magnesite.

5. The flame retardant polymer composition of claim 1, wherein the polymer is a polyolefin.

6. The flame retardant polymer composition of claim 1, wherein the polymer is an elastomer selected from the group consisting of acrylic rubber, ethylene propylene diene rubber, fluoroelastomers, polybutadiene, polyisobutylene, polyisoprene, silicone rubber, and natural rubber.

7. The flame retardant polymer composition of claim 1, wherein the polymer is a thermoplastic polymer selected from the group consisting of acrylic, acrylonitrile butadiene styrene, ethylene vinyl acetate, nylon, poly (vinyl acetate), polyacrylonitrile, polybenzimidazole, polybenzoxazole, polybenzothiazole, polybutene-1, polybutene, polycarbonate, polyethersulfone, polyetheretherketone, polyetherimide, polyethylene adipate, polyethylene terephthalate, polyimide, polylactic acid, polymethyl acrylate, polymethyl methacrylate, polymethylpentene, polyoxymethylene, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, polytetrafluoroethylene, polyvinyl alcohol, polyvinyl chloride, polyvinyl ester, and polyvinylidene fluoride.

8. The flame retardant polymer composition of claim 7, wherein the thermoplastic polymer comprises ethylene vinyl acetate and polyethylene.

9. The flame retardant polymer composition of claim 8, wherein the polyethylene is a linear low density polyethylene.

10. The flame retardant polymer composition of claim 1, further comprising less than 5 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

11. The flame retardant polymer composition of claim 10 comprising less than 0.1 weight percent aluminum hydroxide, relative to the total weight of the flame retardant polymer composition.

12. The flame retardant polymer composition of claim 1 which is substantially halogen free.

13. The flame retardant polymer composition of claim 1, further comprising titanium dioxide.

14. The flame retardant polymer composition of claim 1, wherein the fatty acid is stearin and the polysiloxane is PDMS.

15. The flame retardant polymer composition of claim 1 comprising both fatty acid and polysiloxane in a weight ratio of stearin:polysiloxane range of 1:1 to 6:1.

16. The flame retardant polymer composition of claim 1, further comprising from 0.01 to 0.05 weight percent dicumyl peroxide, relative to the total weight of the flame retardant polymer composition.

17. The flame retardant polymer composition of claim 1 having a density in the range of 1.1 to 1.8g/cm ³.

18. The flame retardant polymer composition of claim 1 having a melt flow rate in the range of 2.0 to 4.5cm ³/10 min at 150 ℃ according to ASTM D1238-10.

19. The flame retardant polymer composition of claim 1 having a melt flow rate in the range of 47-70cm ³/10 min at 230 ℃ according to ASTM D1238-10.

20. The flame retardant polymer composition of claim 1 having a tensile strength at break according to ASTM D638-14 in the range of 6-10 MPa.

21. The flame retardant polymer composition of claim 1 having a tensile strain at break in the range of 15-40% according to ASTM D638-14.

22. The flame retardant polymer composition of claim 1 having a UL94 flammability rating of V-0 or V-1.

23. An insulated wire product comprising:

A conductive wire coated with a layer of the flame retardant polymer composition of claim 1.

24. A method of preparing the flame retardant polymer composition of claim 1, the method comprising:

A polysiloxane or fatty acid coated mineral blend is melt mixed with the polymer.

25. The method of claim 24, wherein the polysiloxane or fatty acid coated mineral blend has an average diameter in the range of 0.5-10 μm.

26. The method of claim 24, wherein the BET surface area of the polysiloxane or fatty acid coated mineral blend is in the range of 2-20m ²/g.

27. The method of claim 24, wherein the melt mixing is performed in a screw extruder having an RPM in the range of 100-300 and is heated at a temperature gradient having a maximum temperature in the range of 150-250 ℃.

28. The method of claim 24, wherein the melt mixing comprises first melt mixing the polymer in a heated screw extruder and then adding the mineral blend to the heated screw extruder.

29. A method of forming a flame retardant object, the method comprising:

Heating the flame retardant polymer composition of claim 1 to form a molten composition; and

30. The method of claim 29, wherein the object is an electrical conductor, an automotive component, a building material, an electronic device, or an electrical appliance.

31. A method of forming a flame retardant object, the method comprising:

Injection molding the flame retardant polymer composition of claim 1 to form a flame retardant object.

32. The method of claim 31, wherein the flame retardant object forms an outer shell or surface of an electrical conductor, an automotive component, a building material, an electronic device, or an electrical appliance.

33. The method of claim 24, wherein the kaolin is surface treated with a surface treatment agent, and the surface treatment agent is present in an amount of up to 5wt%, based on the total weight of the kaolin.

34. The flame retardant polymer composition of claim 1, wherein the kaolin is surface treated with a surface treatment agent, and the surface treatment agent is present in an amount of up to 5 wt%, based on the total weight of the kaolin.